Botob fob elastic-pi



35 available.

Patented Aug. 25, 192.5.

UNITED STATES;

PATENT oFFicE.

'OSCAR JUNGGREN, OF SCHENECTADY, 'NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A. CORPORATION F NEW YORK.

-Application mea pnrao, 192s. serial no. saam.

To all whom t may concern:

l Be it known that l, OsoAz" a citizen of the United States, residin at Schenectady, county of Schenectady, tate 5 of New York, have invented certain new and useful Improvements in Rotors for Elastic- Fluid. Turbines, of which the following is a specification. Y y Y This invention relates to rotors for elasticfi'aid turbines and an` improved method of constructing theI same, the object being to provide a rotor which may be built up of any dlsired number of simple, easily manufactured sections to form a rugged, lightweight, unitary structure in which said sections form a hollow shaft.

To this end, the present invention, which is herein described andv illustrated in its application to rotors for small steam turbines, provides a rotor having a hollow shaft formed of a multiplicity of tubular-hubbed stage wheels aligned one upon the other and joined together by fusion of metal at the i engaging surfaces. This gives a rotor structure which is as light as and somewhat more flexible than that of thev common hollow shaft type with the wheels carried on said shaft. Y This construction vreadily lends itself to 80 assembling into a rotor as many wheels as may berequired to provide the' proper number of stages for any installation, to eX- Ktract the energy from the elastic liuid at the pressure andv temperature supplied or Hence it will be seen that lin connection with small steam turbines which are built to meet a large variety of operating conditions upon which to a great extent the number of wheels u sed is dependent, the

40 present invention provides a convenient and eflicient means for building up a correspondingly great variety of rotors to meet these conditions economically, from astandard stock of wheels of few sizes.

Fora consideration of what is considered to be novel and the invention, attention is directed to the following description, claims appended thereto and the accompanying drawing.

l0 In the drawing, Fig. 1 is aside view,

5 pressed and drawn out vfrom their centers.

partly in section, of "one embodiment of the -anvention and Fig. 2 is asimilar view of a modification.

Referring particularly to Fig. 1, 3 indicates a number of turbine bucket wheels arranged to form a series of ordinary stages. These wheels are simple disks carrying buckets, indicated at 4, at their peripheries and are formed with hollow projecting hubs The wheels are centered with respect to a common axls and held in proper spaced axial relation by a' shouldered lportion of each hub being pressed into a corresponding counterbore in the next succeeding wheel hub as indicated at 6, such that when fitted together they form a unitary 'rotor structure with what is substantially a hollow shaft 7. Since this hollow shaft is formed by the wheels' themselves, it is automatically extended as more wheels are added and collateral with this desirable feature is the light weight and economyV of material accruing from the hollow shaft construction.

To provide a set of bearings for the assembled rotor, a shouldered hub is-.forced into either end of the hollow .bore as indicated at 8. These hubs are provided with a suitable bearing surface as indicated at 9 and a tapered end portion 10, to which last mentioned portion any suitable form of driving connection, for example, a shaft coupling may be fitted. c

The portions of the shouldered hubs 8 which extend within the wheel bore are axially counterbored as indicated at 11 to permit the hubs to expand and contract with the wheels as they are subjected to changing temperatures, without setting up stresses which would tend to cause separation of the wheels from the hubs. 1

It will be noted that the bearing hubs 8, as well as the hubs 5 of the successive stage wheels 3, are fitted with the usual packing lrings indicated at 12, being well 'adapted to carry these rings without any special littings other than circumferential grooves machined or pressed into said hubs. Y

When the rotor parts are ready for linal assembly, the required number of wheels 3 100 yare arranged in the desired order between the bearing hubs 8 and are then drawn together into the assembled unit as shown in the drawing. They are held in this assembled relation firmly boundtogether by a tie rod 13 passed through the center of the structure and threaded at either end to receive clamping nuts, indicated at 14, ywhich are drawn up firmly, against the outer ends of the bearing hubs. To accommodate the rod 13 and to properly locate it at the center of the structure, the bearing hubs 8 are provided w`ith axial passages as indicated at 15. This method of clamping the parts into a firm assembly is used only by way of example as being that which is now considered to be the most desirable, although it will be understood that means other than that employing the rod 13 may be used without departing from the spirit of the invention.

With the rotor assembled and firmly bound together, the interengaging and adjoining surfaces between the individual parts, namely the end hubs, packing rings and wheels, are united into a permanently bonded unitary structure by fusion of metal; for-example by welding or forging the parts together by any suitable method. 'lhc clamping nuts'lfl and the tieN rod 13 may then be removed. The finished rotor is then 4ready`v for use. 4

vReferring to Fig. 2, a modification is shown to which the same reference numerals as used vin connections with Fig. 1 have been applied with the exponent a added.

The differentiating feature of this modification lies in the type of wheel hub cmployed to form the hollow shaft. In forming the wheel hubs by pressing and drawing out the centers of the wheel blanks,.a sufficient quantity of material may not be obtained to provide longshouldered hubs, for example hke those of Fig. 1. Hence as a substitut-e means-to provide suflicient bonding surface for uniting the hub of one wheel to the next, a flange 16 is formed at the end of a short wheel hub 5". This fiange is provided on its face with a short annular shoulder which is forced into a corresponding shallow counterbore in the next wheel as indicated at Gn. The shoulder and counterbore 6 serve in this' modification merely as means for centering each wheel with respect to the next along a common axis of rotation.

The-remainder of this modification. and

j the form and resultingassembly being the same as before described# From the foregoing description in connection with Figs. 1 and 2, which are only by way ol' example, it will be seen that'in accordance with the present invention, a rotor may be built up of any desired number of interengaging parts of simple, easily manufactured design and formed into a unitary structure having an automatically extensible hollow shaft, without the use of -thefcommonly employed separate hollow shaft of fixed length. This permits of great flexibility in construction, especially in connection with. rotors for small elastic-fluid turbines, as these may be built up of standard wheels of few sizes to meet the varying requirements as to steam and other operating conditions in any case. problem of meeting these conditions is, through the present invention', reduced practically to that of deciding how many wheels shall be stacked one on the other to form the required rotor, the ywheel sizes being standardized and the shaft length being automatically taken care of.

It will be understood that the present invention is not necessarily limited to turbine rotors but may be applied in other fields and may bc carried out by other means.

lV hat I claim as new and desire tosecure by Letters Patent of tlie United States, is:

l. A4 rotor for an elastic fluid turbine or the like comprising a hollow shaft and a plurality of wheel members mounted thereon, the wheel members being provided with integral tubular hubs which are arranged in coaxially aligned engagement with each other and united to form said hollow shaft.

2. A rotor for an elastic-fluid turbine or the like comprising a plurality of separate wheel members, each ofwhich is provided with a projecting tubular hub integral therewith, the hubs telescoping one Within the other. and being united to provide a continuoushollow shaft for the rotor.

3. A rotor for an elastic fluid turbine or the like comprising a plurality of wheel` lmembers provided with integral hollow hubs projecting .axially from their centers, said the rotor 'secured in the ends of the hollow` shaft,.and means for uniting the assembled members intoa unitary structure.

'4. A rotor for anelastic fluid turbine or the like comprlsing a plurality of wheel .members each provided with a central axially-extending integral. hub, the hubs serving to center and space said wheel members relatively to each other and being united by fused metal, and end plugs which provide bearings for4 the rotor.

5. A rotor for an elastic Huid turbine or the like comprising a plurality of wheel members provided with integral hollow hubs projecting axially from their centers, said hubs nesting one within the other whereby they serve to center said wheel members s relatively to each other and to provide a hollow shaft orthe rotor, means formed on' the hubs for spacing said wheel members OSCAR JUNGGREN. 

